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Links between global CO_2 variability and climate anomalies of biomes

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Science China Earth Sciences 2008年第5期51卷 740-747页

作者： peter S. BAKWIN School of Earth and Environmental Sciences Queens College City University of New York New York 11367 USA

The global rate of fossil fuel combustion continues to rise, but the amount of CO2 accumulating in the atmosphere has not increased accordingly. The causes for this discrepancy are widely debated. Par- ticularly, the location and drivers for the interannual variability of atmospheric CO2 are highly uncertain. Here we examine links between global atmospheric CO2 growth rate (CGR) and the climate anomalies of biomes based on (1986―1995) global climate data of ten years and accompanying satellite data sets. Our results show that four biomes, the tropical rainforest, tropical savanna, C4 grassland and boreal forest, and their responses to climate anomalies, are the major climate-sensitive CO2 sinks/sources that control the CGR. The nature and magnitude by which these biomes respond to climate anomalies are generally not the same. However, one common influence did emerge from our analysis; the ex- tremely high CGR observed for the one extreme El Nio year was caused by the response of the tropical biomes (rainforest, savanna and C4 grassland) to temperature.

关键词： biomes carbon cycle climate anomaly NDVI El Nio

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Endoscopic mucosal resection in the upper gastrointestinal tract

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World Journal of Gastroenterology 2008年第13期14卷 1984-1989页

作者： Anis Ahmadi peter Draganov Division Gastroenterology Hepatology and Nutrition University of Florida Gainesville Florida 32610 United States

Endoscopic mucosal resection （EMR） is a technique used to locally excise lesions confined to the mucosa. Its main role is the treatment of advanced dysplasia and early gastrointestinal cancers. EMR was originally described as a therapy for early gastric cancer. Recently its use has expanded as a therapeutic option for ampullary masses, colorectal cancer, and large colorectal polyps. In the Western world, the predominant indication for EMR in the upper gastrointestinal tract is the staging and treatment of advance dysplasia and early neoplasia in Barrett＇s esophagus. This review will describe the basis, indications, techniques, and complications of EMR, and its role in the management of Barrett＇s esophagus.

关键词： Endoscopic mucosal resection Mucosal resection Barrett's esophagus Barrett's dysplasia Therapeutic endoscopy

Testing flexible polymer solar cells in near-space

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National Science Review 2023年第5期10卷 105-106页

作者： peter Müller-Buschbaum Department of Physics TUM School of Natural Sciencesand Heinz Maier-Leibnitz-Zentrum(MLZ)Technical University of Munich

Since the big success of the Vanguard1 mission,being the first solar-powered satellite,the use of solar cells in space developed very ***,conventional solar cell technologies for space are based on silicon and GaAs **...

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Treatment of uncomplicated reflux disease

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World Journal of Gastroenterology 2005年第28期11卷 4291-4299页

作者： Joachim Labenz peter Malfertheiner Department of Medicine Jung-Stilling Hospital Siegen Germany Department of Gastroenterology Hepatology and Infectious Diseases University of MagdeburgGermany

Uncomplicated reflux disease comprises the non-erosive reflux disease (NERD) and erosive reflux disease (ERD).The objectives of treatment are the adequate control of symptoms with restoration of quality of life, healing of lesions and prevention of relapse. Treatment of NERD consists in the administration of proton pump inhibitors (PPI) for 2-4 wk, although patients with NERD show an overall poorer response to PPI treatment than patients with ERD owing to the fact that patients with NERD do not form a pathophysiologically homogenous group. For long-term management on-demand treatment with a PPI is probably the best option. In patients with ERD, therapy with a standard dose PPI for 4-8 wk is always ***-term treatment of ERD is applied either intermittently or as continuous maintenance treatment with an attempt to reduce the daily dosage of the PPI (step-down principle).In selected patients requiring long-term PPI treatment,antireflux surgery is an alternative option. In patients with troublesome reflux symptoms and without alarming features empirical PPI therapy is another option for initial management. Therapy should be withdrawn after initial success. In the case of relapse, the long-term care depends on a careful risk assessment and the response to PPI therapy.

关键词： Erosive reflux disease Non-erosive reflux disease Proton pump inhibitor Uninvestigated reflux disease

Design considerations and behavior of reinforced concrete core dams during construction and impounding

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Water Science and Engineering 2016年第3期9卷 212-218页

作者： peter Tschernutter Adrian Kainrath Institute of Hydraulic Engineering and Water Resources Management Vienna University of Technology

Reinforced concrete core dams can be an alternative solution to conventional dam designs either for permanent impounded reservoirs or flood protection and flood-retaining dams. Dams of this type have been constructed in Austria for various reasons and have shown good behavior during operation. For a better understanding of the load-deformation behavior of this type of dams during construction and impounding, numerical simulations were carried out. The interaction between the thin reinforced concrete core and the dam fill material as well as the influence of fill material properties and other main parameters, such as the roughness of the concrete surface and bedding conditions of the concrete core,on the deformation behavior of dams were examined. The results show that high compressive stress is mainly induced by arching effects in the dam body during construction. During the reservoir impounding, the compressive stresses in the core are reduced significantly while the bending moment in the core footing increases. The results also show that the maximum bending moments occur at the core footing and can be significantly reduced by design improvements. The findings in this study can provide general design recommendations for small dams with a central concrete core as a sealing blanket.

关键词： Embankment dam Concrete diaphragm sealing Numerical analysis Concrete core Structural force

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Fluid and Osmotic Pressure Balance and Volume Stabilization in Cells Dedicated to Professor Karl Stark Pister for his 95th birthday

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Computer Modeling in Engineering & Sciences 2021年第12期129卷 1329-1350页

作者： peter M.Pinsky Department of Mechanical Engineering Stanford UniversityStanford94305CAUSA

A fundamental problem for cells with their fragile membranes is the control of their *** primordial solution to this problem is the active transport of ions across the cell membrane to modulate the intracellular osmotic *** this work,a theoretical model of the cellular pump-leak mechanism is proposed within the general framework of linear nonequilibrium *** model is expressed with phenomenological equations that describe passive and active ionic transport across cell membranes,supplemented by an equation for the membrane potential that accounts for the electrogenicity of the ionic *** active ionic transport,the model predicts that the intracellular fluid pressure will be balanced by the osmotic pressure and a new pressure component that arises from the active ionic fluxes.A model for the pump-leak mechanism in an idealized human cell is introduced to demonstrate the applicability of the proposed theory.

关键词： Pump-leak mechanism cell volume regulation active ion transport ion pump membrane transport cell mechanics modified Kedem-Katchalsky equations nonequilibrium thermodynamics phenomenological equations

Idempotent Completions of Operator Partial Matrices

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Acta Mathematica Sinica,English Series 1999年第3期15卷 333-346页

作者： Heydar Radjavi peter Rosenthal Department of Mathematics Shanxi Teachers University Linfen 041004 P. R. ChinaDepartment of Mathematics Statistics and Computing Science Dalhousie University Halifax N.S. B3H 3J5 Canada Department of Mathematics University of Toronto Toronto On M5S 1A1 Canada

Necessary and sufficient conditions are obtained for operator partial 2×2 matrices to have an idempotent completion, and all such completions are parametrically represented.

关键词： Hilbert space Operator matrix Idempotent operator

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Imaging tumor hypoxia:Blood-borne delivery of imaging agents is fundamentally different in hypoxia subtypes

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Journal of Innovative Optical Health Sciences 2014年第2期7卷 12-17页

作者： peter Vaupel Armulf Mayer Department of Radioncology and Radiotherapy University Medical Center 55131 MainzGermany

Dedicated to the memory of Professor Briton Chance on the ccasion of his 100th birthday(July24 th,2013),and remembering mary erciting discussions on the orygenation of breast cancer,ontumor hyporia in general and imaging of the orygenation status of malignant *** tissue subvolumes are a hallmark feat ure of solid malignant tumors,relevant for cancertherapy and patient outcome because they increase both the intrinsic aggressiveness of tumor cells and their resist ance to several commonly used anticancer *** mech-anisms leading to hypoxia are diverse,may coexist within the same tumor and are commonlygrouped according to the duration of their *** hypoxia is mainly caused by difusionlimitations resulting from enlarged intercapilary distances and adverse difusion geometriesand--to a lsser extent--by hypoxemia,compromised perfusion or long-lasting microregionalfow ***,acute hypoxia preferentilly results from transient disruptions in *** each of these features of the tumor microenvironment can contribute to a criticalreduction of oxy gen availability,the delivery of imaging agents(as well as nutrients and anti-cancer agents)may be compromised or remain unaffected,Thus,a critial appraisal of the ffectsof the various mechanisms leading to hypoxia with regard to the blood-bome delivery of imagingagents is necessary to judge their ability to correctly represent the hypoxic phenotype of solidmalignancies.

关键词： Delivery of imaging agents tumor hypoxia hypoxia subty pes,chronic hypoxia acutehypoxia.

Phytochrome-regulated Gene Expression

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Journal of Integrative Plant Biology 2007年第1期49卷 11-20页

作者： peter H. Quail Department of Plant and Microbial Biology University of Cafifomia Berkeley CA 94720 USA U.S. Department of Agriculture/Agriculture Research Service-Plant Gene Expression Center 800 Buchanan Street Albany CA 94710 LISA

Identification of all genes involved in the phytochrome （phy）-medieted responses of plants to their light environment is an important goal in providing an overall understanding of light-regulated growth end development. This article highlights end integrates the central findings of two recent comprehensive studies in Arabidopsis that have identified the genome-wide set of phy-reguleted genes that respond rapidly to red-light signals upon first exposure of dark-grown seedlings, and have tested the functional relevance to normal seedling photomorphogenesis of an Initial subset of these genes. The data：（a） reveal considerable complexity in the channeling of the light signals through the different phy-femily members （phyA to phyE） to responsive genes; （b） identify a diversity of transcription-factor-encoding genes as major early, if not primary, targets of phy signaling, end, therefore, as potentially important regulators in the transcriptional-network hierarchy; and （c） identify auxin-related genes as the dominant class among rapidly-regulated, hormone-related genes. However, reverse-genetic functional profiling of a selected subset of these genes reveals that only a limited fraction are necessary for optimal phy-induced seedling deetioletion.

关键词： expression profiling phytochrome signaling transcriptional networks microarrays reverse genetics functional profiling transcription factors auxin-related genes